Gas turbine



April 3, 1962 E. D. CONKLIN ETAL GAS TURBINE Original Filed Jan. 15,1954 4 Sheets-Sheet l Attorney April 3, 1962 Original Filed Jan. 15,1954 E. D. CONKLIN ETAL 3,027,717

GAS TURBINE 4 Sheets-Sheet 2 1 \Zl. J

A ril 3, 1962 E. D. CONKLIN ETAL GAS TURBINE 4 Sheets-Sheet 3 OriginalFiled Jan. 13, 1954 m m w v April 1952 E. D. CONKLIN ETAL 3,027,717

GAS TURBINE Original Filed Jan. 15, 1954 4 Sheets-Sheet 4 Inventors a 6Y fig? ttoney United States Patent M 3,027,717 GAS TURBINE Emmett D.Conkiin, Warren, Eugene E. Flanigan, De-

troit, James M. Ricketts, Oxford, and William A. Turunen, Birmingham,Mich., assignors to General M0- tors Corporation, Detroit, Mich., acorporation of Delaware Original application Jan. 13, 1954, Ser. No.403,824, new Patent No. 2,972,230, dated Feb. 21, 1961. Divided and thisapplication Jan. 28, 1959, Ser. No. 789,705

3 Claims. (Cl. 6039.65)

This application is a division of application Serial No. 403,824, filedJanuary 13, 1954 (Patent No. 2,972,230).

This invention relates to a power plant of the gas turbine type. Theprincipal object of the invention is to provide a superior gas turbinepower plant installation particularly suitable for automobiles.

More specifically, objects of the invention are to provide a compact gasturbine engine and to provide a novel and improved arrangement ofcompressor and combustion chamber in a gas turbine.

The preferred embodiment of the invention is in a gas turbine enginecomprising a centrifugal compressor, combustion chambers suppliedthereby, a first turbine powered by combustion products from thecombustion chambers and coupled to the compressor, and a second turbinedriving 'a power output shaft which is coupled through suitable powertransmission gearing to the drive wheels of the car. The nature andadvantages of the novel structures according to the invention will bemore clearly apparent from the succeeding detailed description and theaccompanying drawings, in which:

FIG. 1 is an elevation view of an automobile turbine installation, theoutline of the automobile being indicated by broken lines;

FIG. 2 is a plan view of the same;

FIG. 3 is a sectional view taken on a plane containing the axis of theengine, showing principally the combustion chamber;

FIG. 4 is an exploded view of the compressor case and diffuser, and

FIG. 5 is an elevation view of the diffuser taken on the plane indicatedin FIG. 4.

' FIGURE 6 is a front elevation view of the engine taken on the planeindicated by the line 6-6 in FIG- URE 1.

FIGURE 7 is a cross section of the engine taken on the plane indicatedby the line 77 of FIGURE 1.

Referring first to FIGS. 1 and 2, these illustrate the installation ofan engine according to the invention at the rear end of an automobile,the body of which is immaterial and may be considered as indicated inoutline by .the broken lines 11. The car includes longitudinal framemembers 12 and a rear frame cross member 13. The frame may beconventional. The rear wheels are indicated at 14. The rear suspensionand drive are of a de Dion type, the details of which are immaterial tothis invention.

The engine, transmission, and differential gear constitute an assemblywhich may be mounted in the vehicle as a unit and which comprises, ingeneral terms, a radialflow compressor 16 receiving air through an inlet17 and discharging it into combustion chambers 18 and 19 from which itflows through turbine wheels mounted within a casing 21. The exhaustgases are discharged through a pipe 22 to the rear end of the vehicle.This pipe is of saddle shaped contour at the forward end and overlies atransmission 23 which includes speed reduction and reverse gears and adifferential gear through which the half shafts 24 of the rear wheels 14are driven. The compressor, combustion chambers, turbine, transmission,and

3,027,717 Patented Apr. 3, 1962 exhaust pipe are mounted on a subframewhich comprises a rail 26 at each side of the power plant and a crossmember 27 at the rear. The front ends of the rails 26 are bolted at 28to the outer case or air collector scroll 29 of the compressor. Theentire power plant assembly is supported on the chassis frame 12, 13 ofthe vehicle at three points. Brackets 31 extending from the rails 26 aremounted by conventional shock absorbing supports on pads on the frame.The rear cross member 27 is mounted by bolt 32 and a shock absorbingmount to a pad on the rear frame cross member 13. By virtue of the threepoint mounting of the power plant and the de Dion type rear axle, thepower plant is easily installed and removed and is not affected bydistortions of the chassis or movements of the rear wheels.

The details of the power plant will be clearer after general discussionof the engine structure. Referring additionally to FIGS. 3 to 7, it willbe seen that the compressor case 29 defines not only the collectorchamber or scroll 33 but also the forward cover of the compressor andthe air inlet portion 34 which is coupled by a V band clamp 36 to aflaring air entrance duct 37 on the front of which is mounted a screen38. An engine oil cooling radiator 39 is mounted in the path of airentering the engine. The compressor case is completed by a back plate 40bolted to the front plate 29 by studs and nuts (not illlustrated) andbolts 77.

A centrifugal compressor rotor 42, which may be of known type comprisingan inducer or entry portion 43 and an impeller or discharge portion 44-,is mounted on a main shaft (not illustrated) supported in an engineframe or drive shaft housing 52, extending between the compressor andturbine. The housing or frame 52 is fixed to the compressor case rearplate 40 by studs including studs 56.

Air discharged from the compressor rotor 42 flows into a diflfuser 63which comprises a unitary member defining a plate curving away from theback plate 40 toward the outer margin and spiral ribs 64 thereon whichact as guide vanes for the discharged air. The plate 63 has a flange 66at the inner edge which is piloted on the case 29. A disk or annularplate 67 is fixed to the forward face of the diffuser 63 by screws 68and this entire assembly is held on the case 29 by bolts 69.

The air collector scroll comprises two circumferentially enlargingportions of approximately extent, each of which discharges into one ofthe combustion chambers 18 and 19. The compressor case is formed atpoints 180 apart with cylindrical portions 71, the axes of which areparallel to the compressor axis. These cylindrical portions 71 definethe intermediate part of the two combustion chambers, each of which alsocomprises a forward shell 72 and a rear shell 73 aligned with thecylinder 71. The forward shell 72 is integral with a flange secured tothe forward face of the cylinder 71 by bolts 74. The compressor rearplate 40 is also formed with two circular openings 76 which registerwith the cylindrical portions 71. A flange on the rear shell 73 is fixedto the case 29 by bolts 77 passing through the rear plate 40 into thecylindrical portion 71, which constitute part of the means by which thecompressor casing parts 29 and 40 are held together.

The rear combustion chamber shell 73 comprises two generally cylindricalparts 78 and 79 connected by a bellows type expansion joint 81 of knowntype to provide for thermal expansion. Combustion takes place within thecombustion chamber 18 in a flame tube or combustion liner 82 which iscomprised of a number of sections 83 united by corrugated strips 84welded to the sections and a forward cap or dome 86. The parts 82 and 83may, of course, be provided with openings for admission of air in asuitable pattern, which are not illustrated. Air also enters the forwardend of dome 86 through a swirler 87. A fuel nozzle 88, the internalstructure of which is immaterial to the invention, is bolted to theforward end of shell 72 and piloted within the swirler 87, providing asupport for the forward end of the flame tube.

An igniter or spark plug 89, which may be of known type and thestructure of which is also immaterial to the invention, is mounted inthe shell 72 and extends through the dome 86.

As appears most clearly in FIG. 2, each half of the collector scrollportion of the compressor case 29 increases in width circumferentiallyof the engine and it also increases slightly in its radial dimensioncircumferentially of the engine so as to increase in cross sectiontoward each of the combustion chambers into which it discharges. Thecylindrical portion 71 which constitutes a part of the combustionchamber also constitutes a termination of the particular halfcircumference of the collector. The extreme distance of this portionfrom the axis of the engine is but very slightly greater than the radiusof the beginning portion from the axis as will be apparent from theslight amount to which the parts '71 project outside the forward end ofthe frame rails 26.

By mounting the combustion chamber into the diffuser as is done in thisengine instead of completing the diffusion of the air and then turningthe air into an outlet which discharges it into the combustion chamber,a far more compact structure than that of conventional engines isachieved. In other words, the necessary diameter of the compressordiffuser and collector substantially determines the diameter of theengine. As will be apparent from FIG. 5, the diffuser plate 63 isslightly notched at the margin at 63' to provide clearance for thecombustion chamber liner so that the liner is as close to the axis ofthe engine as is consistent with proper diffusion and discharge of air.

The discharge of air into the mid-portion of the combustion chamberallows the combustion chamber to project forwardly to approximately thesame plane as the air inlet and brings the turbine close to thecompressor, making possible a short rigid main shaft connecting thecompressor and turbine, which is another important advantage of theconstruction according to the invention.

With the compressor-diffuser combustion chamber arrangement of theinvention, some difliculty was experienced with combustion which wasfound to be the result of swirl of air circumferentially around thecombustion chamber liner which interfered with proper flow patternsthrough the combustion chamber liner. This problem was solved byproviding a baflie extending longitudinally of the liner andsubstantially from the wall of the flame tube to the wall of thecombustion chamber. This baflle constitutes a strip 92 of sheet metalwelded as indicated at 93 to each of the sections of the combustionchamber. The preferred position for this strip is approximately at themiddle of the leeward side of the liner with respect to the position ofthe air inlet to the combustion chamber. However, in the view of FIG. 3,it is shown rotated some 45 above this position so as to show moreclearly. With the baffle thus mounted, the air entering the combustionchamber divides and flows around each side of the liner and toward eachend of the liner and the flow into the liner is quite satisfactory.

Details of the turbines, shafts therefor, etc., immaterial to theinvention of this application are omitted in the interest ofconciseness. Reference may be made to the parent application Patent No.2,972,230, for such details.

The turbine inlet casing or scroll 122 defines tWo openings 123 atopposite sides of the engine axis to receive the combustion products.The scroll 122 is mounted within the forward end of an outer turbinecase of heat shield 125 which has flanged openings 126 abutting theentrance portions 123 of the scroll.

Combustion products are conducted from the combustion chamber into theinlets 123 to the turbine through concentric inner and outer ducts orelbows 137 and 138. The outer conduit 137 is provided with flanges whichare secured to the parts 79 of the combustion chamber by V band clamp139, and similarly to the turbine inlet 123 by clamp 141. The liner 138is spaced from the outer conduit 137 at its discharge end by sheet metalspacers 142 and at its forward end by a flange 143 on the elbow whichextends into a recess between the flanges on the parts 79 and 137 forlocation. The rear end of the combustion liner 82 is telescoped withinthe forward end of the discharge elbow 138 and is provided with a flange144 which engages the outer surface of the elbow to align the two parts.It will be apparent that this sliding joint provides for relativeexpansion of the parts.

Combustion chamber temperature is measured by a thermocouple v mountedin any suitable manner in the elbow 137 and projecting through anopening in the liner 138. The structure of the thermocouple and thedetails of the mounting are immaterial to the present invention.

The outer wall of the combustion chamber is not constituted to resistthe pressure exerted against the ends by the air within the chamberbecause of the thermal expansion joint 81. This pressure, therefore,tends to distort the turbine nozzle because the combustion chambersexert forces of considerable magnitude along an axis outboard of thenozzle. These forces are compensated for in large measure whileretaining the ability of the combustion chamber to adjust to thermalconditions by an arrangement comprising a strap 152 fixed by bolts 74 tothe forward end of the portion 71 of the compressor case and coupled toa bracket 153 welded to the elbow 137. The rear end of the strap islooped around a rod 154 through which a bolt 155 is threaded. A stack156 of Belleville washers is compressed between the head of the bolt 155and the flange of the bracket so as to pull on the strap 152. Theexpansion of the combustion chambers can be accommodated by compressionof springs 156 and, if desired, these springs may have a very low rateso that the tension varies little with the movement.

An oil filter 251 is mounted on the engine case 52, the nature of thefilter and its connection into the lubrication system being immaterialto the present invention.

The principal support of the gas generator is the bolting of thecompressor case 29 to the front end of the rails at 28 as shown inFIG. 1. In addition, a relatively thin deep plate 260 extends betweenthe rails over the outlet of combustion chamber 19 and under the outletof combustion chamber 18. This plate is fixed to the rear end of theaccessory gear case 52 immediately ahead of the turbine. The plate 260is fixed to the side rails by bolts 261 (-FIG. 1) through angle brackets262. The plate is rigid in a vertical direction but flexible fore andaft so that it can bow slightly to accommodate expansion due to heat.

The transmission 23 is supported by plates 270 and 271 which are similarto the plate 260 and extend from one rail to the other. The plate 271 issufliciently stiff to resist any fore and aft movement of thetransmission, while the plate 270 is relatively flexible in the fore andaft direction. Both of these plates are of deep enough section to resistany vertical movement of the transmission, or rotation thereof about alongitudinal axis. It will be seen, therefore, that all the parts of thepower plant are supported on the subframe in a simple and efficientmanner providing for relative movement as necessary and preventing anyundesired movement of the parts.

The entire installation is particularly suited for automobile purposesbecause of the power characteristics of the gas coupled turbine andbecause of the compactness and ease of installation of the power plant.

The detailed description herein of the preferred embodiment of theinvention is not to be construed as limiting the scope of the invention.

We claim:

1. A gas turbine engine comprising, in combination, a radial-flowcompressor having an axis and including a compressor casing defining avaned difiuser and an air collector scroll, a generally cylindricalcombustion case supplied with air from the collector scroll, the outerboundaries of the scroll and case relative to the axis being closelyadjacent and the case extending axially in both directions from thescroll, the case being defined by the compressor casing and shellsmounted on and extending from each face of the casing, and a combustionliner having a fuel inlet at one end thereof and a combustion productsoutlet at the other end thereof mounted Within the case and extendingaxially in both directions from the scroll, the scroll discharging intothe case through an air inlet directed transversely to said axisintermediate the ends of the liner.

2. A gas turbine engine comprising, in combination, a radial-flowcompressor having an axis and including a compressor casing defining avaned diffuser and an air collector scroll, a generally cylindricalcombustion case supplied with air from the collector scroll, the outerboundaries of the scroll and case relative to the axis being closelyadjacent and the case extending axially in both directions from thescroll, the case being defined by the compressor casing and shellsmounted on and extending from each face of the casing, a combustionliner having a fuel inlet at one end thereof and a combustion productsoutlet at the other end thereof mounted within the case and extendingaxially in both directions from the scroll,

the scroll discharging into the case through an air inlet directedtransversely to the said axis intermediate the ends of the liner, and afixed bafile extending radially and 1ongitudinally of the casesubstantially from the liner to the case disposed on the opposite sideof the liner from the air inlet to inhibit circumferential flow of airin the space between the casing and liner.

3. A gas turbine combustion chamber comprising a generally cylindricalcasing, a flame tube therein extending longitudinally of the casing, acombustion products outlet at one end of the casing, a fuel inlet at theother end of the casing, an air inlet directed substantially radi allyinto the casing intermediate the ends of the casing and of the flametube, the casing and flame tube defining between them an annular spaceconnecting the air inlet with the entire circumference of the flametube, and a bafiie extending radially and longitudinally of the casingbetween the casing and flame tube generally opposite to the air inlet toinhibit circumferential swirl of air in the space between the casing andflame tube.

References Cited in the file of this patent UNITED STATES PATENTS2,470,184 Pfenninger May 17, 1949 2,601,000 Nerad June 17, 19522,746,246 Valota May 22, 1956 2,800,093 Burg July 23, 1957 2,801,518Wosika Aug. 6, 1957

